On May 10, 2010, at 10:57 AM, WS7I wrote:
> I'll let Chen address the phase-shift and polar problems. But don't use your
> 250 Hz filters as they won't work!
Yep, unlike the P5/4L4FN case (50 baud), you will need to use a wider filter
for this one. Perhaps something around 90 Hz wider than the narrowest filter
that you could use for "regular" RTTY.
Jay is also right that multipath is a bigger problem since intersymbol overlap
(mark and space overlapping) is more significant due to the shorter bit time.
That is on top of the fact that Eb/No (the normalized "SNR per bit") is reduced
since Eb (energy per bit) is reduced due to the shorter bit time.
We'll find out if this is just a poor choice, or is a very poor choice :-) :-).
73
Chen, W7AY
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